module pe.app.loading {

  /**

   * Backing file loading screen.

   * This class is ViewModel bound to DOM with Knockout.js.

   * Parametrized with an ArrayBuffer loading function (async)

   */

  export class LoadFile {

    className = ko.observable('');

    shortText = ko.observable('');

    progressRatio = ko.observable(0);

    private static _loadWorkPart = 0.2;

    constructor(

      arrayBufferSource: (callback: AsyncCallback<ArrayBuffer>) => void,

      yieldScheduler: AsyncCallback.YieldCallback) {

      var callback: any = (error, arrayBuffer) =>

        this._arrayBufferComplete(error, arrayBuffer);

      callback.progress = (current, total, text = this.shortText()) => {

        this.progressRatio(LoadFile._loadWorkPart * current / total);

        this.shortText(text);

      };

      this.className('pe-loading-getdata');

      this.shortText('wait');

      this.progressRatio(0);

      arrayBufferSource(callback);

    }

    private _arrayBufferComplete(error: Error, arrayBuffer: ArrayBuffer) {

      if (error) {

        this.className('pe-loading-error');

        this.progressRatio(1);

        this.shortText(error.message);

        return;

      }

      this.className('pe-loading-unmanaged');

      this.shortText('PE headers');

      this.progressRatio(LoadFile._loadWorkPart);

      //TODO: read PE headers, then read Assembly

    }

  }

}